Cutoff regulators in chiral nuclear effective field theory

TL;DR

This paper proposes a cutoff regularization scheme in chiral nuclear effective field theory that systematically compensates for symmetry violations caused by regulators, enabling more consistent calculations.

Contribution

It introduces a method to correct symmetry violations from cutoff regulators in chiral EFT, allowing combined use of dimensional and cutoff regularization schemes.

Findings

The scheme systematically compensates for chiral and Lorentz symmetry violations.

Dimensional regularization can be used selectively alongside cutoff regulators.

The method improves the consistency of multi-nucleon calculations.

Abstract

Three-dimensional cutoff regulators are frequently employed in multi-nucleon calculations, but they violate chiral symmetry and Lorentz invariance. A cutoff regularization scheme is proposed to compensate systematically at subleading orders for these symmetry violations caused by regulator artifacts. This is especially helpful when a soft momentum cutoff has to be used for technical reasons. It is also shown that dimensional regularization can still be used for some Feynman (sub)diagrams while cutoff regulators are used for the rest.